1. Field of the Invention
This invention relates to electrically conductive silicone rubber compositions. More particularly, this invention relates to curable, electrically conductive silicone rubber compositions which upon curing are characterized by the bleeding out at an appropriate rate of a specified silicone oil at the surface of the cured compositions.
2. Description of the Prior Art
Conventional silicone rubber molded products which have been coated, impregnated, or blended with a polydimethylsiloxane oil or a polymethylphenylsiloxane oil and which do not contain carbon black exhibit the thermal, chemical, and cold resistance and low compression set of the silicone rubber itself, in addition to an excellent releasability due to the bleeding-out of the silicone oil on the surface of the cured molded product. For this reason, such products are used in a wide variety of applications such as sealants, gaskets, boots, connectors, lamination rolls, expander rolls, textile-printing rolls, and heat-fixer rolls. In particular, molded silicone rubber products which have been impregnated or blended with a silicone oil will bleed out a constant quantity of silicone oil and can be simply and inexpensively manufactured. This is an advantageous situation.
However, an electrically conductive silicone rubber containing carbon black and one of the aforementioned silicone oils will not bleed out the silicone oil on the surface of the molded silicone rubber. Various methods were examined by the present inventors in order to remedy this shortcoming.